1. Field of the Invention
The present invention relates to an improved system for data processing incorporating a rotatable magnetic recording disk and, more particularly, to a system including such a disk, a jacket for protecting the disk, and a liner mounted on an interior wall of the jacket to wipe across the disk when it is rotatably driven.
2. Description of the Prior Art
It is well known to store information for data processing systems on rotatably-driven magnetic disks. Information on such magnetic disks may be written (i.e., stored) or read (i.e., retrieved) by selectively positioning a magnetic transducer, called a read/write head, at the surface of the rotating disk. It is also well known that such disks can be made flexible or "floppy", and in such instances that it is necessary to provide a permanent shell or protective jacket, analagous to an envelope cover for a phonograph record, so that the disk remains planar during rotation. It is also known that jackets for such floppy disks may be rigid shells or may have some flexure. As used herein, the term jacket should be understood to include both flexible and rigid shells. Such jackets must, of course, have openings formed therein so that the disk can be connected to a drive device and so that the read/write transducer can be postioned immediately adjacent to the face of the disk.
Because of the necessary openings in the jackets for flexible magnetic recording disks, a frequently encountered problem with usage of such disks is that foreign matter, such as dust particles, may contact the surface of the disk and cause errors in recording or retrieving information on the disk. To minimize errors arising from such causes, it is known to provide soft liners on the interior of a disk jacket and to provide means which cause flexure of the jacket, or the liner, to gently press the liners against the face of the disk to wipe foreign material from the disk during rotation and, thereby, prevent dust particles and the like from reaching the read/write transducer.
In the prior art, U.S. Pat. No. 3,864,755 discloses a protective cartridge for a disk, with the flat interior walls of the cartridge coated with a low-friction porous material to wipe against the opposed faces of the disk.
Similarly, U.S. Pat. No. 4,254,864 discloses a protective jacket for holding a rotatable magnetic disk between two flat buffer sheets bonded to the inner surfaces of the jacket. The patent suggests that the buffer sheets may be either formed as a flat annulus or as a flat spiral with respect to the axis of rotation of the magnetic disk.
As still another example of prior art, U.S. Pat. No. 4,413,298 discloses a flat sheet of fabric mounted to the interior of a diskette jacket to wipe against the surface of a rotatable disk. According to this patent, the wiping fabric may be formed from tissue or from a flocked-fiber layer. Likewise, U.S. Pat. No. 4,251,843 discloses a flat layer of fabric fixed to the interior of a protective jacket to clean the surface of a rotatable magnetic disk. And again, a flat wiping sheet is shown mounted within a protective cover for a disk in U.S. Pat. No. 3,668,658.
In practice, where a deformable protective jacket or envelope is used in combination with a flat wiping sheet as described herein above, it is typical to provide a rigid supporting member, usually called a platen, integral to the disk drive and then to provide a pressure pad to press against the outside of the jacket so as to deform it in a manner which presses the wiping sheet or a wiping pad into contact with the disk. As to jackets which are rigid (i.e., not deformable), it is known to mount a spring member, such as one made of a plastic film, polyester or the like, within the rigid jacket and to position a section of wiping material so that the distal portion of the spring member forces the wiping material against the face of the disk.